Fatal error: Class 'Symfony\Component\Debug\Exception\FlattenException' not found in /var/www/html/dev/spa/vendor/symfony/http-kernel/Symfony/Component/HttpKernel/Exception/FlattenException.php on line 26

Call Stack:
    0.0003     229656   1. {main}() /var/www/html/dev/spa/vendor/symfony/http-kernel/Symfony/Component/HttpKernel/Exception/FlattenException.php:0